FDA Chantix assessment finds slight heart risk

A year after modifying its label to comply with FDA concerns that smoking cessation aid Chantix could increase the risk of heart problems, Pfizer got word that the FDA's deep-dive into Chantix studies shows an elevated – but not statistically significant – risk to heart health.

The agency, which released its findings yesterday, looked at major adverse events, including cardiovascular-related death, nonfatal myocardial infarction and nonfatal stroke. The report comes days after the journal Circulation published a study that found that women smokers increased their risk of sudden cardiac death by 8% every five years they smoked, compared to women who never smoked.

This most recent Chantix announcement does not indicate that an additional label change is needed, and SEC filings indicate that 2011 label change has already inflicted damage to the brand. Third quarter financials attribute part of the recent sales decline when compared to the year before – 6% for the quarter ended September 30, 9% for the nine months ended September 30 -- to the new label, in addition to “negative media exposure across several key markets.” FDA data indicates that healthcare providers issued around 2.3 million Chantix prescriptions between September 2011 and September 12 for 1.26 million patients.

Brand sales also took a hit last year, sliding 5% in 2011 compared to 2010, but a new label has not been the only thing to hound the smoking treatment: several plaintiffs allege that the drug has been linked to suicide or suicide attempts.

The CDC reports that just over 19% of US adults smoke, contributing to the 303 billion cigarettes that were sold in the US in 2010. Quitting medications include over-the-counter nicotine patches or lozenges, as well as prescription medications like Pfizer's Chantix (varenicline) or GlaxoSmithKline's Zyban (bupropion).

Pfizer did not respond to questions about how the latest news could affect sales or what the company would do with the drug, whose patent runs through 2020. A company spokesman did note in an email that the heart issues that did surface “occurred primarily in patients with known cardiovascular disease.”

The company also wrote that Chantix has been shown “to increase the likelihood of abstinence from smoking for as long as one year compared to treatment with placebo” and that the drug “is an important treatment option for adult smokers who want to quit.”